1. Field of the Invention
The present invention relates to a vehicle-mounted device, and is, for example, preferably applied to an audio video device mounted on a vehicle (this audio video device will be referred to as vehicle audio video device, hereinafter).
2. Description of the Related Art
An existing vehicle audio video device is designed to store a large amount of music content in a hard disk or the like situated inside the vehicle audio video device.
In many cases, such a vehicle audio video device classifies and manages the pieces of music content under a hierarchical structure of directories. By operating the vehicle audio video device, a user goes from an upper stratum to a lower stratum to search for his desired pieces of music content (see Jpn. Pat. Laid-Open Publication No. 2004-157661, for example).